. The long term goal of the proposed study is to determine whether testing for oncogenic types of HPV should be used, either in conjunction with, or in place of cytology, for screening women to detect CIN 2-3. Specifically, the sensitivity and positive predictive value of different screening strategies for identifying women with CIN 2-3 will be determined. Strategies include: 1) a single or repeated abnormal Pap smear; 2) a single or repeated positive assay for oncogenic HPV types; 3) one abnormal Pap smear (detected after re-screening all cytologically negative smears from HPV DNA positive women); 4) one abnormal Pap smear and one positive HPV DNA assay (in parallel or in series); and 5) detection of oncogenic types of HPV DNA in urine. Current studies examining the etiology of CIN 2-3 versus CIN 1 will be continued. The study will test the hypothesis that among women with cervical HPV 16 infection, the type of infecting HPV variant, as well as characteristics of the infected epithelial cells (i.e, immature and proliferating cells versus mature and non proliferating cells) are associated with histologic changes consistent with CIN 2-3 versus CIN 1. The screening and histopathology data will be used in conjunction with information from the literature, the NCI-sponsored Survival, Epidemiology, and End Results (SEER) Program, Medicare and Medicaid databases, and community physicians to evaluate the cost effectiveness of different approaches to cervical cancer control. The proposed studies are intended to contribute to understanding of the pathogenesis of cervical caner and to have important public health implications for cervical cancer control.